1. Field of the Invention
This invention relates to a compound bow and more particularly to a compound bow having a continuous cable which is reeved about pulleys eccentrically positioned on the limbs of the bow and is adjustable to vary the draw tension and draw length of the cable which is aligned with the longitudinal axis of the bow to eliminate torque on the limbs at all times.
2. Description of the Prior Art
Compound bows, as well known in the art, utilize eccentrically positioned bow string or cable mounting devices secured to the free ends of the bow limbs. The cable or arrow string is reeved around the eccentric devices which include wheels, pulleys and the like and are operable to provide a mechanical advantage to increase the amount of potential energy stored in the limbs as the arrow string is drawn. With this arrangement when the arrow string is in the full draw position, maximum potential energy is stored in the bow, but the force required to maintain the arrow string in the full draw position is less than the maximum draw weight of the bow. As the bow string is being drawn the draw weight or force applied to the bow increases to a maximum draw weight and lets off to a lower draw weight at the full draw position. Maximum energy is stored in the limbs without requiring maximum force to be applied to the arrow string to hold the arrow string at the full draw position. This substantially improves the performance of the bow and ease of operation.
Examples of compound bows utilizing eccentric pulleys are disclosed in the following U.S. Pat. Nos.: 3,486,495; 3,958,551; 4,054,118; 4,061,124 and 4,064,862. However, a problem is encountered with mounting the cable upon the eccentric pulleys in a manner to prevent contact between the cable and a released arrow's fletching so as not to interfere with the flight of the arrow or damage the arrow fletching. Therefore, suitable devices such as auxiliary cable adjustment deflectors, such as pulleys, illustrated in U.S. Pat. No. 4,054,118 have been utilized to deflect the cable from the sight window where the arrow is mounted on the bow. With this arrangement the cable will not contact the arrow when the arrow is released from the bow. A channeled cable deflector sold by Trueflight Manufacturing Co., Inc. is operable when clamped onto the portion of the cable opposite the arrow shaft to remove the cable from contact with the arrow shaft.
However, moving the tension cable out of the path of a released arrow by reeving the cable around additional pulleys to deflect the cable from the longitudinal axis of the bow and remove the cable from alignment with the longitudinal axis of the bow exerts a torque upon the limbs of the bow. This introduces stress upon the limbs which after a period of time may damage the limbs and/or substantially reduce the consistency and accuracy to be obtained by the bow. Therefore, there is need to provide in a compound bow apparatus for mounting the cable on the pulleys in a manner which removes the cable from contact with the fletching of a released arrow without subjecting the limbs of the bow to a torque and furthermore by an arrangement which permits adjustments in the draw tension of the cable.